A NATION AT WAR: CHEMICAL WARFARE

By ANDREW C. REVKIN

Published: April 2, 2003

As American-led forces push toward Baghdad, the shrink-wrapped $200 suits that troops are carrying to protect against chemical and biological weapons could soon have their first real-world test, and experts and officials are divided over how well they will work.

The suits, made of a carbon-laced fabric imported from Germany, have been successfully tested against a variety of toxic substances in military laboratories and at a half-dozen military proving grounds over the last six years, according to the Pentagon.

But whether they perform just as well in combat, and particularly in the rising heat expected later this week, is another matter, government officials and independent experts said yesterday. Daytime temperatures between Baghdad and Basra are likely to approach 100 degrees from Thursday into the weekend, forecasters say.

The nine-pound suits are far more comfortable, durable and light than the gear used in the 1991 Persian Gulf war. But in high heat the new suits can still cause the wearer to sweat profusely and, together with a tightly sealed gas mask, bring on feelings of claustrophobia, military veterans who have worn them said.

In addition, protection is guaranteed only if the suit is properly put on, even in chaotic battlefield conditions.

Another potential issue is time. Once a suit is contaminated, it must be replaced within 24 hours. If there are protracted battles on contaminated terrain, even the current supplies could be exhausted, some government officials said.

Over the last two days, troops heading toward Baghdad have been placed on high alert for chemical attacks, military officials said, based on the idea that Saddam Hussein might lash out with everything in his inventory if defeat is near.

If that occurs, ''this will be the real truth teller,'' said Ray J. Decker, the director of the office of defense capabilities and management at the General Accounting Office, which in 2001 criticized the Defense Department's handling of its stockpile of older protective gear.

Only on the battlefield can the reliability and performance of a new piece of equipment be judged, he said. ''Did the equipment perform as well as designed, did the troops perform as well as they trained, and did the exercises reflect the realities of the battlefield?'' he said. ''This is what this will come down to.''

In its report, the G.A.O. found, among other problems, that the Pentagon had lost track of about 250,000 defective suits of the vintage used in 1991. Supplies of the older suits could still end up being used in the current conflict if the 1.5 million new suits are exhausted -- an unlikely but conceivable situation, some government experts said.

The new suits were first developed in 1993, both to improve the ability of troops to confront a chemical or biological threat in high heat and to cut costs by extending the life of the suits. The new layered, porous fabric allows air to circulate around the body while trapping lethal substances in tiny beads of absorbent carbon.

There are 1.5 million suits available to the armed forces around the world. Every service member involved in the current war has been issued at least two new suits, officials said, with each designed to last 45 days once the wrapping is removed. Already, because of alerts in some battles, some troops have had to put on their suits, starting the clock. The older suits lasted 30 days.

The new suits can also be washed up to six times in that span, while the older suits could not be washed at all.

In a possible reflection of lingering concerns, commanders in the field are telling troops in Iraq to don the suits over their conventional uniforms if a chemical attack is detected or imminent, even in high heat.

''The suits are always worn over uniforms for maximum protection,'' said Lt. Cmdr. Charles L. Owens, a spokesman for the United States Central Command in Qatar.

The Army field manual, in contrast, recommends that ''individuals, when directed, wear the overgarment over underwear when heat stress is expected to be a significant factor.''

Gus Pagonis, a retired three-star Army general who directed logistics in the 1991 war, said he was confident that the increase in combat training for chemical attacks since then would protect troops.

''In the last 10 or 12 years, the threat has become far more prevalent so they've done even more exhaustive training,'' he added. ''That doesn't mean it's not going to be a hardship. But they've been trained for this.''

Photo: The fabric has resisted poisons in laboratories and at proving grounds, the Pentagon says. (Department of Defense) Chart: ''Shielding Against a Chemical Attack'' The Mission Oriented Protective Posture (MOPP) calls for protective gear to be worn in several configurations, depending on the perceived level of threat from chemical or biological weapons. MOPP LEVEL 0 WHEN USED: Heightened alert, but no signs of immediate danger. PIECES ON HAND: Overgarments, overboots, mask with hood, gloves MOPP LEVEL 1 WHEN USED: Indications that an attack in the theater is probable. PIECES ON HAND: Overboots, mask with hood, gloves MOPP LEVEL 2 WHEN USED: Indications that an attack in the theater is probable. PIECES ON HAND: Mask with hood, gloves MOPP LEVEL 3 WHEN USED: Chemical and biological agents are present at a negligible risk level. PIECES ON HAND: Gloves MOPP LEVEL 4 WHEN USED: Highest degree of protection when agents are present, but the risk is undetermined. PIECES ON HAND: -- (Source: Federation of American Scientists)